Pre-Medication Drugs Flashcards
Define sedation
induction of CNS depression and drowsiness by the use of drugs
Define dissociative anesthesia
a form of general anesthesia characterized by a catatonic state
- neural information is processed without proper coordination in space and time
What is neuroleptanalgesia?
a state similar to general anesthesia produced by a sedative and analgesic agent
What are the actions of anticholinergics?
- inhibit the parasympathetic nervous system
- antagonists on muscarinic Ach receptors
Atropine
type, solubilty, admin, barriers
- anticholinergic
- lipid soluble
- absorbs well IM, SC, PO
- crosses BBB and placental barrier
Glycopyrrolate
type, solubilty, admin, barriers
- anticholinergic
- water soluble
- absorbs slowly IM, SC, PO
- doesn’t cross BBB or placental barrier
- onset of effect slower than atropine
What are the indications for anticholinergics?
- increasing heart rate (opioid induced bradycardia, reflex bradycardia)
- decreasing salivation and bronchial secretion
What are the contraindications for anticholinergics?
- tachycardia
- hyperthyroidism
- most heart diseases
- narrow angle glaucoma
What are the effects of alpha-2 agonists on pre-synaptic membranes?
- sedation
- analgesia
- reduction of sympathetic outflow from brain
- reduction of stress response (decreases NE and EP blood levels)
Where are the post-synaptic membrane alpha-2 receptors located, and what are their effects?
- wall of arteries and veins
- mediate vasoconstriction
Where are the extra-synaptic sites of alpha-2 receptors, and what are the effects?
- adipocytes: inhibition of lipolysis
- pancreatic B-cells: inhibition of insulin release
What are the CV effects of alpha-2 agonists?
- strong vasoconstriction
- reflex bradycardia
- low CO and tissue perfusion
What are the respiratory effects of alpha-2 agonists?
- mild respiratory depression
- decreased RR, increased tidal volume
- upper airway resistance
- V/Q mismatch in horses
- bronchoconstriction, lung edema, hypoexemia, and V/Q mismatch in ruminants
What are the GI effects of alpha-2 agonists?
- decreased salivation
- LES tone decreases
- decreased GI motility
- vomiting
What are the indications for alpha-2 agonists?
- sedation of aggressive animals
- sedation to prevent post-op airway obstruction
- prevention/treatment of seizures
What are the contraindications of alpha-2 agonists?
- too young or too old
- hemodynamic instability
- severely debilitated
- risk patients
Name 5 alpha-2 agonists
Xylazine Dexmedetomidine Medetomidine Detomidine Romifidine
Name 3 alpha-2 antagonists
Atipamezole
Yohimbine
Tolazoline
Which receptors do phenothiazines atagonize?
- dopamine
- serotonin
- alpha-1
- histamine
What are the CNS effects of Acepromazine?
- antagonizes dopamine and serotonin
- weaker sedative than alpha-2 agonists
- no analgesic
- antiemetic
- mild respiratory depression
What are the CV effects of Acepromazine?
- antagonist on alpha-1 receptors
- vasodilation and hypotension
What are the indications for phenothiazines?
- mild sedation
- prevention/treatment of opioid dysphoria
- prevention of emesis caused by morphine
- sedation for dogs with laryngeal paralysis
- enhance sedative effect of xylazine in horses
What are the contraindications for phenothiazines?
- hyovolemia, hemodynamic instability
- Von-Willebrand disease
What are Benzodiazepines, and what are their main effects?
- GABA agonists
- sedative, anticonvulsant, muscle relaxant
- minimal CV and respiratory effects
- no analgesia
